The present invention relates generally to a manner by which to communicate packet-based data in a mobile communication system in which communication handovers are effectuated between radio access points. More particularly, the present invention relates to apparatus, and an associated method, by which to more efficiently provide a temporary identifier to a mobile node with which a communication handover is to be effectuated. The present invention further advantageously provides apparatus, and an associated method, by which more efficiently to perform handoff evaluations, responsive to which communication handovers are effectuated. Through operation of an embodiment of the present invention, more efficient communications are effectuable.
Advancements in communication technologies have permitted the development, and introduction, of new types of communication systems of improved characteristics. Such new types of communication systems have generally permitted the communication of data at increased throughput rates or made more convenient, or even possible, the transmission of data in various communication applications.
The advancements in communication technologies have, for example, permitted the introduction and popularization of new types of radio communication systems. The radio communication systems are advantageously utilized as radio links to form at least portions of communication paths formed between sending and receiving stations of the radio communication systems. Conventional wireline connections are obviated in lieu of the use instead of radio links. Increased communication mobility, relative to conventional wireline communication systems, is thereby generally possible when communications are effectuated by way of a radio communication system.
A cellular communication system is exemplary of a radio communication system which has been made possible as a result of advancements in communication technologies. A cellular communication system, in general, is formed of a network infrastructure which is installed through a geographic area. Spaced-apart fixed-site transceivers define cells of the communication system. A subscriber to the cellular communication system is capable of communicating therethrough by way of a mobile station when positioned within the geographic area encompassed by the network infrastructure of the cellular communication system. Normally, a radio link is formed between the mobile station and the fixed-site transceiver which defines the cell at which the mobile station is located when communications are to be effectuated. Because of the mobility permitted of the mobile station, during an ongoing communication session, the mobile station might travel out of one cell and into another. To permit continuation of the communication session, a handover of communications of the mobile station between the fixed-site transceiver defining the respective cells is performed. Continued communications with the mobile station is thereby permitted.
Other types of radio communication systems are operable in manners analogous to cellular communication systems. That is to say, other types of radio communication systems provide for mobility of a mobile transceiver and handovers of communications with successive fixed-site transceivers. A WLAN (wireless local area network) constructed pursuant to the IEEE 802.11 standard, for instance, utilizes handover procedures analogous to those utilized in a cellular communication system.
More generally, such types of radio communication systems can be represented by a mobile node, i.e., a mobile station, which is connected, by way of a radio link, with a radio access point of a radio access network. Handovers are effectuated to successive radio access points of the radio access network as the mobile node travels through an area encompassed by the radio access network.
When the communication system utilizes a packet-based communication scheme, such as an IP (internet protocol) communication scheme, packets of data are communicated between sending and receiving stations of the communication system. A data packet includes a header portion and a payload portion. The header portion identifies the destination to which the packet of data is to be communicated, and the payload portion forms the informational portion of the data packet. Additional complexity in the identification of the destination, indicated by the header portion of the data packet, occurs in a communication system in which destination is a mobile node. Due to the mobile nature of the mobile node, routing of a data packet thereto is made more difficult, particularly by way of a radio access network which includes a plurality of radio access points, any of which can be connected, by way of a radio link, with the mobile node.
In an Ipv6 system, for instance, a mobile node is assigned an IP address and further utilizes a care-of-address when the point of attachment to the radio access network changes. Two manners are conventionally utilized by which to assign an IP address to a mobile node. The manners are referred, respectively, as a stateless autoconfiguration method, and a stateful autoconfiguration method.
Utilization of either conventional method, however, necessitates a delay in the assignation of a care-of-address when a handover of communications of the mobile node is effectuated. In communication applications in which delays must be minimized, such as voice communications and multimedia communications, the delay in the assignation of the address deleteriously affects the communications. Problems are particularly evident when an ongoing multimedia of voice communication session is in progress when the handover of communications, and concomitant new address assignation procedures are carried out.
Additionally, handover evaluations carried out prior to the initiation of a handover of communications necessitates the evaluation of various measurement indicia. When the measurement indicia is communicated utilizing packet-based data, significant signaling is required to provide the necessary information to perform the handover evaluation. Such signaling increases the complexity of the communication system as well as also introducing delays which deleteriously affect communications in the communication system.
What is needed, therefore, is a manner by which better to assign addresses to a mobile node to reduce delays associated with conventional techniques.
What is further needed is a manner better able to provide the necessary information to perform a handover evaluation.
It is in light of this background information related to communications in a packet-based, mobile communication system that the significant improvements of the present invention have evolved.
The present invention, accordingly, advantageously provides apparatus, and an associated method, by which to communicate packet-based data in a mobile communication system in which communication handovers are effectuated between radio access points.
Through operation of an embodiment of the present invention, a manner is provided by which to more efficiently provide a temporary identifier to a mobile node of which communications therewith are to be handed over between radio access points of the mobile communication system. Also, through operation of an embodiment of the present invention, a manner is provided by which more efficiently to perform handoff evaluations, responsive to which communication handovers are effectuated.
In one aspect of the present invention, handover evaluation procedures are performed at a radio access point in which active communications are ongoing with a mobile node. Responsive to the handoff evaluation performed at the active radio access point, a handover of communications is effectuated to permit continued communications of the mobile node with a target radio access point. Because the handoff evaluation procedure is performed at the radio access point, lesser amounts of signaling to perform the handoff evaluation procedure is required in contrast to conventional handoff evaluations procedures which are conventionally performed at a central point.
In another aspect of the present invention, both the active and target radio access points are interconnected, thereby to permit measurements performed at the target radio access point to be provided to the active radio access point. And, the mobile node provides indications of communication characteristics in its ongoing communications to the active radio access point. Handoff evaluations are performed responsive thereto.
In another aspect of the present invention, the active and target radio access points are not interconnected. An initial handoff evaluation procedure is performed taking into account measurements made by the mobile node of communication characteristics of its ongoing communications with the active radio access point. Results of the initial handoff evaluation process are thereafter sent to a central point. The central point is, in turn, connected to the target radio access point and measurements are solicited from the target radio access point of communication conditions thereat. A subsequent handoff evaluation process is performed at the central point and a decision to perform a handover of communications of the mobile node from the active radio access point to the target radio access point is made at the central point.
In another aspect of the present invention, a temporary identifier which is used to identify a mobile node is provided to the mobile node prior to a handover of communications with the mobile-node from an active radio access point to a target radio access point. Because the allocation of the temporary identifier is made prior to the handover, delays conventionally associated with assignation of an identifier to identify a mobile node subsequent to its handover to a target radio access point are obviated.
In one implementation, a mobile, packet-based communication system is provided in which communications are effectuated pursuant to Ipv6 protocols. The communication system includes a network infrastructure and a mobile node. Network infrastructure includes a radio access network portion and a core network portion. A DHCP server is positioned at the network infrastructure. The server includes a cache of temporary identifiers. Responsive to requests therefor by radio access points of the radio application network, temporary identifiers are provided to the radio access points. Prior to handover of communications of a mobile node connected to an active radio access point, a temporary identifier is allocated by the active radio access point to identify the mobile node as a care-of-address. Thereby, a temporary identifier is already assigned to the mobile node prior to its handover to a target radio access point. And, delays conventionally associated with assignation of identifiers to identify the mobile node subsequent to handover of communications to the target radio access point are obviated.
In these and other aspects, therefore, apparatus, and an associated method is provided for a wireless communication system having a mobile node operable to communicate by way of a network infrastructure with another communication node. The mobile node is moveable between a first position and at least a second position. When positioned at the first position, the mobile node is operable to communicate by way of a first subnetwork of the network infrastructure. When positioned at the at least the second position, communication handover is effectuated such that the mobile node is operable to communicate by way of a subnetwork of the mobile node. A temporary identifier is provided to the mobile node to identify the mobile node, thereby to permit routing of data packets thereto. A detector is coupled to detect indications of a decision to handover communications of the mobile node between the first and second subnetworks. An assignor is coupled to the detector. The assignor assigns the temporary identifier to the mobile node subsequent to detection by the detector of when the handover is to be effectuated and prior to effectuation of the handover.
A more complete appreciation of the present invention and the scope thereof can be obtained from the accompanying drawings which are briefly summarized below, the following detailed description of the presently-preferred embodiments of the invention, and the appended claims.